One of the most effective methods for air purification is photo catalysis. Photo catalysis occurs when a photo catalyst is irradiated by ultra-violet light in the UV-A, UV-B and UV-C range. In a typical application, a UV-irradiated surface is coated with a photo catalytic material such as titanium dioxide. Photo catalysis occurs on a very thin boundary layer above the surface of the photo catalyst. This presents one of the limitations of photo catalysis for air or water purification, since it is difficult to bring all the fluid to be purified to the UV-irradiated photo catalyst. This invention addresses this limitation and presents a novel method to move a fluid past an irradiated photo catalyst.
Photo-catalysis is generally defined as “acceleration by the presence of a catalyst”. A catalyst does not change in itself or being consumed in the chemical reaction. This definition includes photosensitization, a process by which a photochemical alteration occurs in one molecular entity as a result of initial absorption of radiation by another molecular entity called the photosensitized. Chlorophyll of plants is a type of photo catalyst. Compared to photosynthesis, in which chlorophyll captures sunlight to turn water and carbon dioxide into oxygen and glucose, photo catalysis with light and water creates a strong oxidation agent to break down any organic matter to carbon dioxide and water.
Photo catalysis is effective for sterilizing, deodorizing, and purifying fluids such as air or water. However, conventional fluid purification systems do not take advantage of photo catalysts.